ANTIBIOTIC RESISTANCE PATTERN OF PSEUDOMONAS ...

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P.aeroginosa showed that colistin was active against 95.6% of isolates followed by amikacin, imipenem, doripenem, cefepime (91.3%), ceftazidime (86.9%), ...
Volume: 4: Issue-9: September-2015

ISSN:2278-0246 Coden : IJAPBS

www.ijapbs.com

ANTIBIOTIC RESISTANCE PATTERN OF PSEUDOMONAS AERUGINOSA IN PATIENTS WITH OTITIS IN TEHRAN HOSPITALS Mohammad Mahdi Karimi Yazdi1, Zohreh Ghalavand1, Alireza Karimi Yazdi 2, Ali Hashemi1, Maryam Pourhajibagher3, Akbar Jelodar4, Mozhgan Esmaeili Benvidi1, Gita Eslami*1 1

Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciencse, Tehran, Iran. 2 Otolaryngology Research Center, Tehran University of Medical Sciences, Tehran, Iran. 3 Department of Microbiology, School of Medicine, Tehran University of Medical Sciencse, Tehran, Iran. 4 Golpayegani hospital, Qom, Iran. *Corresponding author: Gita Eslami Postal Address: Shahid Beheshti University- School of Medicine- Department of Microbiology Tel: 02123872556 Email: [email protected]

ABSTRACT: Background: Pseudomonas aeroginosa is one of the main agents of otitis. There are two types of otitis. Otitis media (OM) is acute, chronic or recurrent. There is high prevalence of OM in children. Inflamation or infection of pinea and ear canal called otitis externa (OE), can occur in human and some other creatures like dog. OE or swimmer’s ear is common in summer. The aim of this study is to identify outbreak of P.aeroginosa involved in OE and OM and drug sensitivity of this bacterium. Materials and methods: All samples were taken from 186 patients who admitted in Emam Khomeini, Shahid shouride and Amiralam hospitals by otolaryngologists in Tehran, Iran, from October 2014 to July 2015. These Samples were taken from infected ears with cotton swabs and cultured in Muller Hinton, Citrimide and MacConkey Agar mediums, then incubated for 24- 48 hours in 37oC. Antibiotic testing was done using disk diffusion method. Results: Twenty-two out of 186 samples were positive for P.aeroginosa (%12.3). Drug sensitivity pattern of P.aeroginosa showed that colistin was active against 95.6% of isolates followed by amikacin, imipenem, doripenem, cefepime (91.3%), ceftazidime (86.9%), ciprofloxacin, gentamicin, levofloxacin (78.2%) and aztreonam (73.9%).

International Journal of Analytical, Pharmaceutical and Biomedical Sciences Available online at www.ijapbs.com

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ISSN: 2278-0246

Conclusion: Almost all the drugs that tested were effective against P.aeroginosa but the most effective drug was colistin. Especialists prescribe ciprofloxacin drobs more than other antinbiotics in clinics, because of their effective advantages. Therefore more investigation with larger sample size is essential.

Keywords: Pseudomonas aeroginosa, otitis media, external otitis, Disk Diffusion Antimicrobial Tests. INTRODUCTION Pseudomonas aeruginosa is an epitome of important Gram-negative opportunistic pathogens that can cause various diseases, including otitis media (OM), otitis externa (OE), osteomyelitis, hot tub folliculitis, menin¬gitis, endocarditis, pneumonia, urinary tract infection and septi¬cemia (1- 3). OM is an inflammation of the middle ear associated with P. aeruginosa infection which can be seen in two forms of acute OM (AOM) and chronic suppurative OM (CSOM) (4). Accumulation of P.aeruginosa population in ear occur due to dermal edema, changes in the ear canal, narrowing of the lumen and formation of anaerobic environment in ear following reduction of ventilation, and increasing of humidity and temperature (5). OE is an infection or inflammation of the external auditory canal (EAC) that most of people will be affected by it in their lives (6). OE is caused by a bacterial infection specially P.aeroginosa, although the condition can also be caused by irritation, fungal infections and allergies (7). In addition of P. aeruginosa, various microorganisms are involved in OE and OM that the most commonly found agents including S aureus, Coagulase- Negative Staphylococci (CNS) and fungii such as Aspergillus and C.albicans (8, 9). There are many factors for creating these infections, but the most common is excessive moisture that enhance the pH and eliminate the cerumen. Hence keratin debris absorbs the water, which creates a nourishing medium for microbial growth (10). Despite appropriate anibiotic therapy, the morbidity and mortality rate due to P. aeruginosa infections is high (11). Unfortunately, P.aeruginosa is intrinsically resistant to a wide range of antibiotics which could be mediated by several agents such as low permeability of P. aeruginosa outer membrane, production of hydrolyzing enzyme, efflux pupms and mutations in genes encoding the target sites of antibiotics (12, 13). On the other hand, the widespread use of antibiotics in recent years has been caused P.aeruginosa resistances to different classes of broad-spectrum antibiotics, thereby jeopardizing the selection of appropriate treatment (14). The purpose of this study was to assess the current in vitro activity level of ten antimicrobial drugs from different antibiotic groups against P. aeruginosa in patients with OE and OM.

MATERIALS AND METHODS: Samples collection In this study, sampling was done by otolaryngologists from patients with suspected to OM and OE infections that referred to Imam Khomeini, Shahid shouride and Amiralam hospitals, Tehran, Iran, from October 2014 to July 2015. During the mentioned period, a total of 186 samples were collected. In order to prevent contamination of samples in clinic, cleaning the ear canal should be done before sampling, so an ear, nose and throat specialist (ENT) or his assistance cleaned ear canal from infected debris or cerumen before suctioning under clinical microscope. Then with striled cotton applicator throw striled ear spaculom and striled condition infected material was obtained.

International Journal of Analytical, Pharmaceutical and Biomedical Sciences Available online at www.ijapbs.com

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P. aeruginosa isolation and identifi¬cation Ear secretions were cultured on Nutrient agar and MacConkey's media (Merk, Germany), and incubated in 37°C. Pri¬mary identification of P. aeruginosa and other organisms were done based on the conventional biochemical tests, including Gram staining, growth on cetrimide agar, growth at 42°C, Kligler iron agar, oxidase, catalase, pigment production, and oxidative-fermenta¬tive (OF) tests. Antibiotic susceptibility test Antibiotic susceptibility was done by Kirby-Bau¬er’s disk diffusion method on Muller-Hinton agar (Merk, Germany) according to the Clinical Laboratory Standard Institute (CLSI) recommendations. The antibiotic disks (MAST, UK) applied were ciprofloxacin (CIP, 5 μg), aztreonam (ATM 30μg), ceftazidime (CAZ 30μg), amikacin (AMK 30μg), imipenem (IPM 10μg), gentamicin (GM 10μg), cefepime (CPT 30μg), doripenem (Dor 10μg), levofloxacin (LVF 5μg) and colistin (CO 25μg). P. aeruginosa standard strain (ATCC 27853) was used as the quality control. They were incubated at 37°C for 18- 24 hours. The diameter of the zone of inhibition was measured and compared to that of standard strain. Statistical analysis SPSS ver. 18.0 (SPSS Inc., Chicago, IL, USA) was used for statistical analysis. Both susceptibility and resistance were calculated as percentages with 95% confidence intervals and statistical significance was defined as a Pvalue